1. yymmdd (see Y2K). Values that are allowed correspond to dates in the range 19510101 to 20501231.
2. yyyymmdd with values in the range 19010101 to 20991231.
3. yyddd (see Y2K). Values are 00001 to 99365 which correspond to dates in the range 19510101 to 20501231.
The fourth option is no date which terminates the program.
Any other invalid input calls the help file.
AJulian dates
Date information is valid from 19000301 till 21000228 but as these years are not leap years the week and day values will not be correct so input is limited to 1901 to 2099.
The program allows input of valid and some invalid dates and converts the values to the nearest real date and evaluates the difference between entered dates and today.
EG. 20000231 will be allowed but converts to the real date 20000302.
ADate input
Dates can be put in three ways:
1. yymmdd (see Y2K). Values that are allowed correspond to dates in the range 19510101 to 20501231.
2. yyyymmdd with values in the range 19010101 to 20991231.
3. yyddd (see Y2K). Values are 00001 to 99365 which correspond to dates in the range 19510101 to 20501231.
There is a fourth option of no date which terminates the program.
Any other invalid input calls the help file or displays an error message.
1Author
Name: Guy Sturges
Email: Guy@Sturges.ch
%Software
This software is freeware.
Weeks
Week 1 is calculated as starting from the first Monday of the year.
This means week 00 is sometimes known as week 53 of the previous year.
Some years only have 52 weeks and some have 53.
The three digit day is calculated with one representing January 1st.
Day 060 is March 1st for non leap years and February 29th for leap years.
If yymmdd dates are input the cut-off year is 50. This means years <= 50 are in the century 2000 and years > 50 are in the century 1900.
Credits
The algorithms used by this program were derived from the HP67 standard pack program for calculating Julian days and have been adpated for use on the Psion.
%Exit
Enter no date and press Enter.
1Author
Name: Guy Sturges
Email: Guy@Sturges.ch
%Software
This software is freeware.
Weeks
Week 1 is calculated as starting from the first Monday of the year.
This means week 00 is sometimes known as week 53 of the previous year.
Some years only have 52 weeks and some have 53.
The three digit day is calculated with one representing January 1st.
Day 060 is March 1st for non leap years and February 29th for leap years.
If yymmdd dates are input the cut-off year is 50. This means years <= 50 are in the century 2000 and years > 50 are in the century 1900.
Credits
The algorithms used by this program were derived from the HP67 calculator standard pack program for calculating Julian days and have been adpated for use on the Psion.